scholarly journals NUMERICAL STUDY OF WAVE INTERACTION WITH A SUBMERGED POROUS BREAKWATER IN COMBINATION WITH A FLOATING BREAKWATER

2018 ◽  
pp. 38 ◽  
Author(s):  
Arun Kamath ◽  
Athul Sasikumar ◽  
Hans Bihs
Keyword(s):  
Numerical Study ◽  
Coastal Region ◽  
Wave Interaction ◽  
Coastal Protection ◽  
Cfd Model ◽  
Submerged Breakwater ◽  
Direct Wave ◽  
Floating Breakwater ◽  
Visual Impact ◽  
Rubble Mound Breakwaters

Conventional emerged rubble mound breakwaters are commonly built to protect ports and marinas from direct wave action. With increased high-valued developments in the coastal region, engineers have to design innovative coastal protection structures that can provide adequate harbor tranquility with minimum visual impact. One such solution is the combination of a submerged breakwater with a floating breakwater. In this paper, the open-source CFD model REEF3D (Bihs et al. 2016) is used to simulate wave interaction with a submerged porous breakwater with a floating breakwater on the lee side. The wave interaction with the submerged porous breakwater is validated by comparison with experimental data from Hieu and Tanimoto (2006). The validated model is then used to simulate the wave interaction with a combination of the submerged breakwater and the floating breakwater. The transmission coefficient across the combination is calculated to be about 12.5%, demonstrating the possibility to provide harbor tranquility with minimum visual impact.

scholarly journals Consistent Particle Method Simulation of Solitary Wave Interaction with a Submerged Breakwater

Water ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 261 ◽  
Author(s):  
Yaru Ren ◽  
Min Luo ◽  
Pengzhi Lin
Keyword(s):  
Solitary Wave ◽  
Numerical Study ◽  
Wave Interaction ◽  
Taylor Series Expansion ◽  
Particle Method ◽  
Experiment Data ◽  
Submerged Breakwater ◽  
Wave Characteristics ◽  
Spatial Derivatives ◽  
Solitary Wave Interaction

This paper presents a numerical study of the solitary wave interaction with a submerged breakwater using the Consistent Particle Method (CPM). The distinct feature of CPM is that it computes the spatial derivatives by using the Taylor series expansion directly and without the use of the kernel or weighting functions. This achieves good numerical consistency and hence better accuracy. Validated by published experiment data, the CPM model is shown to be able to predict the wave elevations, profiles and velocities when a solitary wave interacts with a submerged breakwater. Using the validated model, the detailed physics of the wave breaking process, the vortex generation and evolution and the water particle trajectories are investigated. The influence of the breakwater dimension on the wave characteristics is parametrically studied.

Numerical Study of Pitch Angle on H-Type Vertical Axis Wind Turbine

2012 ◽  
Vol 499 ◽  
pp. 259-264
Author(s):  
Qi Yao ◽  
Ying Xue Yao ◽  
Liang Zhou ◽  
S.Y. Zheng
Keyword(s):  
Wind Turbine ◽  
Pitch Angle ◽  
Numerical Study ◽  
Vertical Axis ◽  
Azimuth Angle ◽  
Power Coefficient ◽  
Cfd Model ◽  
Vertical Axis Wind Turbine ◽  
Sliding Mesh ◽  
Mesh Technique

This paper presents a simulation study of an H-type vertical axis wind turbine. Two dimensional CFD model using sliding mesh technique was generated to help understand aerodynamics performance of this wind turbine. The effect of the pith angle on H-type vertical axis wind turbine was studied based on the computational model. As a result, this wind turbine could get the maximum power coefficient when pitch angle adjusted to a suited angle, furthermore, the effects of pitch angle and azimuth angle on single blade were investigated. The results will provide theoretical supports on study of variable pitch of wind turbine.

scholarly journals Evaluating the feasibility and advantage of a multi-purpose submerged breakwater for harbor protection and benthic habitat enhancement at Kahului Commercial Harbor, Hawai‘i: case study

2021 ◽  
Vol 3 (2) ◽  
Author(s):  
Yuko Stender ◽  
Michael Foley ◽  
Ku’ulei Rodgers ◽  
Paul Jokiel ◽  
Amarjit Singh
Keyword(s):  
Coral Reef ◽  
Coral Cover ◽  
Ecological Impact ◽  
Coastal Protection ◽  
Benthic Habitat ◽  
Engineering Structures ◽  
Camera System ◽  
Reef Environment ◽  
Submerged Breakwater ◽  
Coral Reef Environment

AbstractConstruction of breakwaters provides an engineering solution for coastal protection. However, little effort has been made toward understanding the ecological impact on local coral reef ecosystems and developing engineering structures that would enhance the coral reef environment. A submerged breakwater proposed for Kahului Commercial Harbor, Hawai‘i, provided an opportunity to design a multi-purpose ‘reef structure’ to mitigate wave impacts while providing new coral reef habitat. This design involved ecological and environmental considerations alongside engineering principles, serving as a model for environmentally sound harbor development. This field study evaluated environmental conditions and reef community composition at the proposed site in a gradient extending outward from the harbor, using in situ data with multivariate analyses. Benthic and topographic features in the area were assessed using a towed drop camera system to relate to biological factors. Results that support breakwater topography should follow the natural spur and groove and depth of the adjacent reef and orient with wave direction. A deep area characterized by unconsolidated substrata and low coral cover would be replaced with the shallow, sloping hard bottom of the breakwater, and provide an exemplary area for corals to flourish while protecting the harbor from large ocean swells. Surfaces on shallow sloping hard bottoms receive higher levels of irradiance that benefits coral growth. Optimal levels of water motion facilitate sediment removal and promote coral recruitment and growth. The design of the Kahului Harbor submerged multi-purpose structure serves as a model for design of shoreline modification that enhances, rather than degrades, the local coral reef environment.

Numerical Study on the Effect of a Submerged Breakwater Seaward of an Existing Breakwater for Climate Change Adaptation

2018 ◽  
Author(s):  
Athul Sasikumar ◽  
Arun Kamath ◽  
Onno Musch ◽  
Arne Erling Lothe ◽  
Hans Bihs
Keyword(s):  
Climate Change ◽  
Numerical Model ◽  
Transmission Coefficient ◽  
Numerical Study ◽  
Protective Measure ◽  
Test Case ◽  
Relative Width ◽  
Optimal Dimension ◽  
Submerged Breakwater ◽  
Design Storm

In coastal areas, climate change is causing mean sea level rise and more frequent storm surge events. This means the breakwaters are expected to withstand the action of more severe incident waves and larger overtopping rates than they were designed for. Therefore, these impacts may have a negative effect on the functionality such as overtopping above the acceptable limits, in addition to stability of these structures. A breakwater which has been partly damaged by a storm stronger than the design storm has weak spots that can easily be damaged further. One way of protecting these breakwaters subjected to climate change is to build a submerged breakwater on the seaward side. This study focuses on the use of numerical model for optimal dimension of a submerged breakwater to be used as a protective measure for an existing structure. Comparisons are made between transmission coefficient predicted in the numerical model and those calculated from different formulae in literature. The variation in transmission coefficient due to different relative submergence and relative width parameters for waves with different steepness is studied and curves showing the dependence of these parameters on wave transmission are made. These results are then used for a test case in Kiberg, Norway where a submerged breakwater is proposed in front of a existing damaged rubble mound breakwater. The optimal geometry generated on the basis of curves is then implemented in the local-scale finite element wave prediction model, CGWAVE.

scholarly journals Development of a conceptual framework for the management of biodiversity and ecosystem services in the Mexican Caribbean

2020 ◽  
Vol 20 (suppl 1) ◽  
Author(s):  
Andrés Sánchez-Quinto ◽  
Julliet Correa da Costa ◽  
Nadia S. Zamboni ◽  
Fábio H. C. Sanches ◽  
Silas C. Principe ◽  
...  
Keyword(s):  
Ecosystem Services ◽  
Coral Reefs ◽  
Conceptual Framework ◽  
Conceptual Model ◽  
Coastal Region ◽  
Ecosystem Model ◽  
Coastal Protection ◽  
Coastal Environments ◽  
Management Actions ◽  
Global Biodiversity

Abstract: Coral reefs and mangroves support rich biodiversity and provide ecosystem services that range from food, recreational benefits and coastal protection services, among others. They are one of the most threatened ecosystems by urbanization processes. In this context, we developed a conceptual framework for the management of biodiversity and ecosystem services for these coastal environments. We based our workflow on two sections: “Information base” and “Governance” and use the Puerto Morelos Coastal region as a case study for coastal protection. Puerto Morelos is between two of the most touristic destinations of Mexico (Playa del Carmen and Cancun) that has experienced an increase of population in the past four decades resulting in an intensification of multiple threats to its ecosystems. We characterized the two ecosystems with a “Management Units” strategy. An expert-based ecosystem services matrix was also described in order to connect mangroves and coral reef ecosystems with the multiple beneficiaries. Then an ecosystem model (conceptual model and Global Biodiversity model) was developed. The conceptual model was useful in understanding the interplay processes between systems regarding the ecosystem service of “Coastal Protection”. The Global Biodiversity model evidenced the human-induced shifts in the biodiversity for mangrove and coral reefs ecosystems. Also, a projection for 2035 of “best” and “worst” scenarios was applied using GLOBIO3. A DPSIR conceptual framework was used to analyze environmental problems regarding ecosystem services maintenance. Finally, we evaluated a set of policies associated with these ecosystems that favor coastal protection integrity. This framework facilitates the identification of the most relevant processes and controls about the provision of coastal protection service. It can also be useful to better target management actions and as a tool to identify future management needs to tackle the challenges preventing more effective conservation of coastal environments.

Mathematical study of wave interaction with a mound type of composite poroelastic submerged breakwater

2016 ◽  
Vol 124 ◽  
pp. 1-12 ◽  
Author(s):  
Yuan-Jyh Lan ◽  
Tai-Wen Hsu ◽  
Fang-Xuan Gan ◽  
Chi-Yu Li
Keyword(s):  
Wave Interaction ◽  
Mathematical Study ◽  
Submerged Breakwater

Optimal sinusoidal submerged breakwater for coastal protection

2021 ◽  
Author(s):  
Muh. Fadhel Atras ◽  
Raynaldi Lalang ◽  
Ikha Magdalena
Keyword(s):  
Coastal Protection ◽  
Submerged Breakwater

scholarly journals Coastal protection work for Batu Mejan Beach, Bali

2019 ◽  
Vol 276 ◽  
pp. 04019
Author(s):  
Pujianiki Ni Nyoman ◽  
Astawa Diputra I Gede ◽  
Jayantari Made W ◽  
Mataram INK
Keyword(s):  
Wave Energy ◽  
Protective Layer ◽  
Minimum Cost ◽  
Public Works ◽  
Coastal Protection ◽  
Submerged Breakwater ◽  
The Public ◽  
International Tourist ◽  
Tourism Destinations ◽  
The Cost

Batu Mejan Beach is an international tourist destination located in the Canggu area of Badung regency, Bali. Due to erosion problems of Batu Mejan Beach the local government installed a revetment system to protect the coast. However, the revetment that was built before for the Batu Mejan Beach is currently ineffective and damaged. To determine the parameters for the construction of a new coastal protection system, the wave energy occurring at the site was evaluated initially as part of this study. A Submerged breakwater with a tetrapod for a protective layer was then chosen as the alternative to reduce the wave energy before reaching the shore and to reduce erosion as well as further deterioration of the existing revetment. A Submerged breakwater is suitable in coastal areas that are used as tourism destinations because the submerged breakwater construction is under the water, therefore the beauty of the beach will not be interrupted. Four models were made with variations in the width and elevation of the breakwater peak. The model was selected which has the minimum value of transmission coefficient and minimum cost. The cost budget plan was determined by using the analytical list of the Public Works and Housing Regulations of 2016. From the analysis, a model was selected with a submerged breakwater height of 2.45 m, length of 110 m, distance gap of 55 m, and the budget of IDR 17,861,989,813.

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